Image Sensor Including Nano-Photonic Microlens Array and Electronic Apparatus Including the Image Sensor

This application is a Continuation of U.S. application Ser. No. 18/216,014, filed on Jun. 29, 2023, which is based on and claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2022-0082762, filed on Jul. 5, 2022, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety.

The disclosure relates to an image sensor including a nano-photonic microlens array and an electronic apparatus including the same.

As the resolution of an image sensor increases, a size of a unit pixel in the image sensor has been gradually decreased. In order to prevent degradation of image quality in a low-light environment, a technique of forming a pixel representing one color by binding a plurality of independent photosensitive cells has been suggested. For example, a pixel representing one color may include a total of four photosensitive cells arranged in a 2×2 format. In this case, an output signal from the pixel may be a sum of output signals from four photosensitive cells. Also, an auto-focusing function may be implemented in a phase-detection auto-focusing method by using the pixel having the four photosensitive cells. For example, an auto-focusing signal may be generated by using differences among signals output from a plurality of photosensitive cells included in one pixel.

Provided are an image sensor having improved light utilization efficiency and auto-focusing function and including a nano-photonic microlens array and an electronic apparatus including the image sensor.

Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments of the disclosure.

According to an aspect of an example embodiment, an image sensor includes: a sensor substrate including a plurality of pixels configured to sense incident light; and a nano-photonic microlens array arranged to face a light incident surface of the sensor substrate, the nano-photonic microlens array including a plurality of nano-photonic microlenses configured to condense the incident light, wherein each pixel of the plurality of pixels includes: a plurality of photosensitive cells that are two-dimensionally arranged in a first direction and a second direction perpendicular to the first direction and are configured to independently sense the incident light, and one or more isolation structures configured to electrically isolate the plurality of photosensitive cells from each other, wherein each nano-photonic microlens of the plurality of nano-photonic microlenses includes a plurality of nano-structures that are configured to output light having a convex phase profile, and wherein the plurality of nano-structures are arranged in a two-dimensional array in a diagonal direction between the first direction and the second direction.

A first interval between two nano-structures that are adjacent to each other in the first direction or the second direction, among the plurality of nano-structures, may be greater than or equal to a second interval between two nano-structures that are adjacent to each other in the diagonal direction, among the plurality of nano-structures.

A first arrangement period of the plurality of nano-structures arranged in the first direction or the second direction may be greater than or equal to a second arrangement period of the plurality of nano-structures arranged in the diagonal direction.

Each nano-structure of the plurality of nano-structures arranged in each nano-photonic microlens of the plurality of nano-photonic microlenses may have a width or a diameter such that a phase of the light after passing through a center portion of each nano-photonic microlens is largest and is reduced away from the center portion of each nano-photonic microlens.

A nano-structure arranged at the center portion of each nano-photonic microlens faces, in a vertical direction, a cross point between a first isolation structure extending in the first direction and a second isolation structure extending in the second direction.

A nano-structure that is closest to the nano-structure arranged at the center portion of each nano-photonic microlens may be arranged so as not to face the one or more isolation structures in a vertical direction.

From among the plurality of nano-structures arranged in each nano-photonic microlens, nano-structures having same widths or same diameters may be arranged in the form of a rectangle inclined in the diagonal direction and surround other nano-structures.

The light after passing through each nano-photonic microlens may have a phase profile formed as a rectangle inclined in the diagonal direction.

A minimum value of the phase of light after passing through each nano-photonic microlens, on a cross-section passing through the center portion of each nano-photonic microlens in the first direction, may be greater than a minimum value of the phase of light after passing through each nano-photonic microlens on a cross-section passing an edge of each nano-photonic microlens in the first direction.

The plurality of nano-photonic microlenses may correspond to the plurality of pixels in a one-to-one correspondence, and each nano-photonic microlens of the plurality of nano-photonic microlenses may be arranged to condense incident light to one pixel from among the plurality of pixels corresponding to the respective nano-photonic microlenses.

In each pixel of the plurality of pixels, the plurality of photosensitive cells may be arranged in a 2×2 array, each nano-photonic microlens of the plurality of nano-photonic microlenses may be arranged to face the plurality of photosensitive cells arranged in the 2×2 array, and a focusing spot formed by each of the plurality of nano-photonic microlenses may be located at a center of the 2×2 array.

Each pixel of the plurality of pixels may include four sub-pixels arranged in a 2×2 array, and the plurality of photosensitive cells are arranged in a 2×2 array in each sub-pixel of the four sub-pixels.

The plurality of nano-photonic microlenses may correspond to the four sub-pixels in a one-to-one correspondence, each nano-photonic microlens of the plurality of nano-photonic microlenses may be arranged to face the plurality of photosensitive cells that are arranged in the 2×2 array so as to condense incident light to a corresponding sub-pixel from among the four sub-pixels, and a focusing spot formed by each nano-photonic microlens of the plurality of nano-photonic microlenses may be located at the center of the 2×2 array including the plurality of photosensitive cells.

The image sensor may further include a color filter layer between the sensor substrate and the nano-photonic microlens array.

The color filter layer may include a plurality of color filters that respectively transmit light of different wavelength bands of the incident light, and each color filter of the plurality of color filters may include one of an organic color filter, an inorganic color filter, or an organic/inorganic hybrid color filter.

The image sensor may further include an anti-reflection layer on a light incident surface of the nano-photonic microlens array.

Each of the plurality of nano-photonic microlenses may further include a dielectric layer filled in a space among the plurality of nano-structures, and a refractive index of the plurality of nano-structures may be greater than a refractive index of the dielectric layer.

Each nano-structure of the plurality of nano-structures may have a circular column shape, a polygonal column shape, a cylindrical shape, or a polygonal container shape.

Each nano-structure of the plurality of nano-structures may include a first nano-structure and a second nano-structure provided on the first nano-structure.

According to an aspect of an example embodiment, an electronic apparatus includes: a lens assembly configured to form an optical image of a subject; an image sensor configured to convert the optical image formed by the lens assembly into an electrical signal; and a processor configured to process a signal generated by the image sensor, wherein the image sensor includes: a sensor substrate including a plurality of pixels configured to sense incident light; and a nano-photonic microlens array arranged to face a light incident surface of the sensor substrate, the nano-photonic microlens array including a plurality of nano-photonic microlenses configured to condense the incident light, wherein each of the plurality of pixels includes: a plurality of photosensitive cells that are two-dimensionally arranged in a first direction and a second direction perpendicular to the first direction and are configured to independently sense the incident light, and one or more isolation structures configured to electrically isolate the plurality of photosensitive cells from each other, wherein each nano-photonic microlens of the plurality of nano-photonic microlenses includes a plurality of nano-structures that are configured to output light having a convex phase profile, and wherein the plurality of nano-structures are arranged in a two-dimensional array in a diagonal direction between the first direction and the second direction.

Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the example embodiments are merely described below, by referring to the figures, to explain aspects. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

Hereinafter, an image sensor including a nano-photonic microlens array and an electronic apparatus including the image sensor will be described in detail with reference to accompanying drawings. The example embodiments of the disclosure are capable of various modifications and may be embodied in many different forms. In the drawings, like reference numerals denote like components, and sizes of components in the drawings may be exaggerated for convenience of explanation.

When a layer, a film, a region, or a panel is referred to as being “on” another element, it may be directly on/under/at left/right sides of the other layer or substrate, or intervening layers may also be present.

It will be understood that although the terms “first,” “second,” etc. may be used herein to describe various components, these components should not be limited by these terms. These components are only used to distinguish one component from another. These terms do not limit that materials or structures of components are different from one another.

An expression used in the singular encompasses the expression of the plural, unless it has a clearly different meaning in the context. It will be further understood that when a portion is referred to as “comprises” another component, the portion may not exclude another component but may further comprise another component unless the context states otherwise.

In addition, the terms such as “ . . . unit”, “module”, etc. provided herein indicates a unit performing a function or operation, and may be realized by hardware, software, or a combination of hardware and software. For example, according to an example, “units” or “ . . . modules” may be implemented by a processor, by one or more hardware components, by one or more electronic components and/or circuits.

The use of the terms of “the above-described” and similar indicative terms may correspond to both the singular forms and the plural forms.

Also, the steps of all methods described herein may be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. Also, the use of all exemplary terms (for example, etc.) is only to describe a technical spirit in detail, and the scope of rights is not limited by these terms unless the context is limited by the claims.

1 FIG. 1 FIG. 1000 1000 1100 1010 1020 1030 1000 is a schematic block diagram of an image sensoraccording to an example embodiment. Referring to, the image sensormay include a pixel array, a timing controller (T/C), a row decoder, and an output circuit. The image sensormay include a charge-coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor.

1100 1020 1100 1010 1020 1100 1010 1030 1030 1030 1100 1010 1020 1030 1030 1010 1020 1030 The pixel arrayincludes pixels that are two-dimensionally arranged in a plurality of rows and columns. The row decoderselects one of the rows in the pixel arraybased on a row address signal output from the timing controller. According to an example embodiment, the row decoderselects one of the rows in the pixel arrayin response to a row address signal output from the timing controller. The output circuitoutputs a photosensitive signal, in a column unit, from a plurality of pixels arranged in the selected row. To this end, the output circuitmay include a column decoder and an analog-to-digital converter (ADC). For example, the output circuitmay include a plurality of ADCs that are arranged respectively to columns between the column decoder and the pixel array, or one ADC arranged at an output end of the column decoder. The timing controller, the row decoder, and the output circuitmay be implemented as one chip or in separate chips. A processor for processing an image signal output from the output circuitmay be implemented as one chip along with the timing controller, the row decoder, and the output circuit.

1100 1100 1000 2 2 FIGS.A toC The pixel arraymay include a plurality of pixels that sense light of different wavelengths. The pixel arrangement may be implemented in various ways. For example,show various pixel arrangements in the pixel arrayof the image sensor.

2 FIG.A 2 FIG.A 1000 shows a Bayer pattern that is generally adopted in the image sensor. Referring to, one unit pattern includes four quadrant regions, and first through fourth quadrants may be the blue pixel B, the green pixel G, the red pixel R, and the green pixel G, respectively. The unit patterns may be repeatedly and two-dimensionally arranged in a first direction (X direction) and a second direction (Y direction). In other words, two green pixels G are arranged in one diagonal direction and one blue pixel B and one red pixel R are arranged in another diagonal direction in a unit pattern of a 2×2 array. In the entire arrangement of pixels, a first row in which a plurality of green pixels G and a plurality of blue pixels B are alternately arranged in the first direction and a second row in which a plurality of red pixels R and a plurality of green pixels G are alternately arranged in the first direction are repeatedly arranged in a second direction.

1100 1100 1000 1100 1000 2 FIG.B 2 FIG.C The pixel arraymay be arranged in various arrangement patterns, rather than the Bayer pattern. For example, referring to, a CYGM arrangement, in which a magenta pixel M, a cyan pixel C, a yellow pixel Y, and a green pixel G configure one unit pattern, may be used. Also, referring to, an RGBW arrangement, in which a green pixel G, a red pixel R, a blue pixel, and a white pixel W configure one unit pattern, may be used. Although not shown in the drawings, the unit pattern may have a 3×2 array form. In addition to the above examples, the pixels in the pixel arraymay be arranged in various ways according to color characteristics of the image sensor. Hereinafter, it will be described that the pixel arrayof the image sensorhas a Bayer pattern, but the operating principles may be applied to other patterns of pixel arrangement than the Bayer pattern.

1100 Hereinafter, for convenience of description, an example in which the pixel arrayhas a Bayer pattern structure will be described as an example.

3 FIG. 3 FIG. 1100 1100 110 120 110 130 120 is a perspective view schematically showing a structure of a pixel arrayin an image sensor according to an example embodiment. Referring to, the pixel arraymay include a sensor substrate, a color filter layeron the sensor substrate, and a nano-photonic microlens arrayon the color filter layer.

4 FIG. 3 FIG. 4 FIG. 110 1100 110 110 111 112 113 114 111 112 113 114 111 114 112 113 is a plan view schematically showing a structure of the sensor substratein the pixel arrayof. Referring to, the sensor substratemay include a plurality of pixels sensing incident light. For example, the sensor substratemay include a first pixel, a second pixel, a third pixel, and a fourth pixelthat convert incident light into electrical signals and generate an image signal. The first pixel, the second pixel, the third pixel, and the fourth pixelmay form one unit Bayer pattern. For example, the first and fourth pixelsandmay be green pixels sensing green light, the second pixelmay be a blue pixel sensing blue light, and the third pixelmay be a red pixel sensing red light.

3 4 FIGS.and 1100 111 112 113 114 show one unit Bayer pattern including four pixels as only an example, but the pixel arraymay include a plurality of Bayer patterns that are two-dimensionally arranged. For example, a plurality of first pixelsand a plurality of second pixelsmay be alternately arranged in a first direction (X-direction), and a plurality of third pixelsand a plurality of fourth pixelsmay be alternately arranged on a cross-section located differently in a second direction (Y-direction) perpendicular to the first direction (X-direction).

111 112 113 114 111 112 113 114 1 2 3 4 1 2 3 4 111 112 113 114 1 2 3 4 Each of the first pixel, the second pixel, the third pixel, and the fourth pixelmay include a plurality of photosensitive cells that independently sense incident light. For example, each of the first pixel, the second pixel, the third pixel, and the fourth pixelmay include a first photosensitive cell c, a second photosensitive cells c, a third photosensitive cell c, and a fourth photosensitive cells c. The first photosensitive cell c, the second photosensitive cells c, the third photosensitive cell c, and the fourth photosensitive cells cmay be two-dimensionally arranged in the first direction (X-direction) and the second direction (Y-direction). For example, in each of the first pixel, the second pixel, the third pixel, and the fourth pixel, the first photosensitive cell c, the second photosensitive cells c, the third photosensitive cell c, and the fourth photosensitive cells cmay be arranged in 2×2 array. However, the disclosure is not limited thereto, and as such, the number of photosensitive cells and/or the arrangement of the photosensitive cells in each of the pixels may be different.

1 2 3 4 1 3 2 4 1 3 2 4 1 2 3 4 According to the example embodiment, an auto-focusing signal may be obtained from a difference between output signals of adjacent photosensitive cells. For example, an auto-focusing signal in the first direction (X-direction) may be generated from a difference between output signals from the first photosensitive cell cand the second photosensitive cell c, a difference between output signals from the third photosensitive cell cand the fourth photosensitive cell c, or a difference between a sum of the output signals from the first photosensitive cell cand the third photosensitive cell cand a sum of the output signals from the second photosensitive cell cand the fourth photosensitive cell c. Also, an auto-focusing signal in the second direction (Y-direction) may be generated from a difference between output signals from the first photosensitive cell cand the third photosensitive cell c, a difference between output signals from the second photosensitive cell cand the fourth photosensitive cell c, or a difference between a sum of the output signals from the first photosensitive cell cand the second photosensitive cell cand a sum of the output signals from the third photosensitive cell cand the fourth photosensitive cell c.

1 2 3 4 1 2 3 4 111 1 2 3 4 112 1 2 3 4 113 1 2 3 4 114 In addition, a general image signal may be obtained by adding output signals from the first to fourth photosensitive cells c, c, c, and c. For example, a first green image signal may be generated by adding the output signals from the first to fourth photosensitive cells c, c, c, and cof the first pixel, a blue image signal may be generated by adding the output signals from the first to fourth photosensitive cells c, c, c, and cof the second pixel, a red image signal may be generated by adding the output signals from the first to fourth photosensitive cells c, c, c, and cof the third pixel, and a second green image signal may be generated by adding the output signals from the first to fourth photosensitive cells c, c, c, and cof the fourth pixel.

111 112 113 114 111 112 113 114 1 2 3 4 111 112 113 114 111 112 113 114 Also, each of the first to fourth pixels,,, andmay include an isolation (DTI) that electrically isolates the plurality of photosensitive cells from one another. The isolation DTI may have, for example, a deep trench isolation structure. The deep trench may be filled with air or an electrically insulating material. The isolation DTI may extend in the first direction (X-direction) and the second direction (Y-direction) so as to divide each of the first to fourth pixels,,, andinto four. The first to fourth photosensitive cells c, c, c, and cin each of the first to fourth pixels,,, andmay be isolated from one another by the isolation DTI. The isolation DTI extending in the first direction (X-direction) and the isolation DTI extending in the second direction (Y-direction) may cross each other at the center of each of the first to fourth pixels,,, and.

111 112 113 114 111 112 113 114 111 112 113 114 Also, the isolations DTI may be arranged in the first direction (X-direction) and the second direction (Y-direction) between adjacent pixels from among the first to fourth pixels,,, and. Therefore, the first to fourth pixels,,, andmay be isolated from one another due to the isolations DTI. The isolation DTI extending in the first direction (X-direction) and the isolation DTI extending in the second direction (Y-direction) may cross each other at the center of the unit Bayer pattern including the first to fourth pixels,,, and.

3 FIG. 120 110 130 120 110 110 120 121 111 122 112 123 113 124 114 111 112 113 114 121 122 123 124 Referring back to, the color filter layermay be arranged between the sensor substrateand the nano-photonic microlens array. The color filter layermay include a plurality of color filters respectively transmitting light of different wavelengths in the incident light. The plurality of color filters may correspond to the plurality of pixels of the sensor substratein one-to-one correspondence. Each of the plurality of color filters may be arranged facing a corresponding pixel from among the plurality of pixels of the sensor substrate. For example, the color filter layermay include a first color filterfacing the first pixel, a second color filterfacing the second pixel, a third color filterfacing the third pixel, and a fourth color filterfacing the fourth pixel. Like the first to fourth pixels,,, and, the plurality of first to fourth color filters,,, andmay be two-dimensionally arranged in the first direction (X-direction) and the second direction (Y-direction).

121 124 122 123 121 122 123 124 For example, the first and fourth color filtersandmay be green filters that transmit light of green wavelength band in the incident light, the second color filtermay be a blue filter that transmits light of blue wavelength band in the incident light, and the third color filtermay be a red filter that transmits light of red wavelength band in the incident light. The first to fourth color filters,,, andmay include organic color filters including an organic dye or an organic pigment.

121 122 123 124 1 2 3 4 111 112 113 114 121 1 2 3 4 111 122 1 2 3 4 112 123 1 2 3 4 113 124 1 2 3 4 114 The first to fourth color filters,,, andmay be arranged to face the first to fourth photosensitive cells c, c, c, and cof the first to fourth pixels,,, andrespectively corresponding thereto. Therefore, the green light that has transmitted through the first color filtermay be incident on the first to fourth photosensitive cells c, c, c, and cof the first pixel, the blue light that has transmitted through the second color filtermay be incident on the first to fourth photosensitive cells c, c, c, and cof the second pixel, the red light that has transmitted through the third color filtermay be incident on the first to fourth photosensitive cells c, c, c, and cof the third pixel, and the green light that has transmitted through the fourth color filtermay be incident on the first to fourth photosensitive cells c, c, c, and cof the fourth pixel.

130 120 110 130 111 112 113 114 110 120 130 131 121 111 132 122 112 133 123 113 134 124 124 131 132 133 134 1 2 3 4 111 112 113 114 111 112 113 114 131 132 133 134 The nano-photonic microlens arraymay be provided on the color filter layerso as to face a light incident surface of the sensor substrate. The nano-photonic microlens arraymay include a plurality of nano-photonic microlenses that respectively condense the incident light to the corresponding pixels from among the first to fourth pixels,,, and. The plurality of nano-photonic microlenses may correspond to the plurality of pixels in the sensor substrateand the plurality of color filters of the color filter layerin one-to-one correspondence. For example, the nano-photonic microlens arraymay include a first nano-photonic microlensarranged on the first color filterso as to face the first pixelin a third direction (Z-direction), a second nano-photonic microlensarranged on the second color filterso as to face the second pixelin the third direction (Z-direction), a third nano-photonic microlensarranged on the third color filterso as to face the third pixelin the third direction (Z-direction), and a fourth nano-photonic microlensarranged on the fourth color filterso as to face the fourth filterin the third direction (Z-direction). Therefore, each of the plurality of first to fourth nano-photonic microlenses,,, andmay be arranged facing the first to fourth photosensitive cells c, c, c, and cof the pixel corresponding thereto from among the first to fourth pixels,,, and. Like the first to fourth pixels,,, and, the plurality of first to fourth nano-photonic microlenses,,, andmay be two-dimensionally arranged in the first direction (X-direction) and the second direction (Y-direction).

131 111 132 112 133 113 134 114 121 124 111 114 122 112 123 113 The first nano-photonic microlenscondenses the incident light to the first pixel, the second nano-photonic microlenscondenses the incident light to the second pixel, the third nano-photonic microlenscondenses the incident light to the third pixel, and the fourth nano-photonic microlenscondenses the incident light to the fourth pixel. In the incident light that is condensed, the light of green wavelength band only passes through the first and fourth color filtersandand is condensed to the first and fourth pixelsand, the light of blue wavelength band only passes through the second color filterand is condensed to the second pixel, and the light of red wavelength band only passes through the third color filterand is condensed to the third pixel.

131 111 132 112 133 113 134 114 121 124 111 114 122 112 123 113 According to an example embodiment, the first nano-photonic microlensmay be configured to focus or direct the incident light to the first pixel, the second nano-photonic microlensmay be configured to focus or direct the incident light to the second pixel, the third nano-photonic microlensmay be configured to focus or direct the incident light to the third pixel, and the fourth nano-photonic microlensmay be configured to focus or direct the incident light to the fourth pixel. According to this configuration, the light of green wavelength band only passes through the first and fourth color filtersandand is focused or directed to the first and fourth pixelsand, the light of blue wavelength band only passes through the second color filterand is focused or directed to the second pixel, and the light of red wavelength band only passes through the third color filterand is focused or directed to the third pixel.

131 132 133 134 131 132 133 134 131 132 133 134 131 132 133 134 The first to fourth nano-photonic microlenses,,, andmay each have a nano-pattern structure that may condense the incident light. The nano-pattern structure may include a plurality of nano-structures NP which change a phase of the incident light to be different according to incident positions in the respective first to fourth nano-photonic microlenses,,, and. Shapes, sizes (widths and heights), intervals, and arrangement types of the plurality of nano-structures NP may be determined such that the light immediately after passing through each of the first to fourth nano-photonic microlenses,,, andmay have a certain phase profile. According to the phase profile, a focal length of the light after passing through each of the first to fourth nano-photonic microlenses,,, andmay be determined.

5 FIG. 3 FIG. 3 FIG. 5 FIG. 130 130 130 is a plan view schematically showing a structure of the nano-photonic microlens arrayaccording to an example embodiment of. Referring toand, the nano-structures NP of the nano-photonic microlens arraymay each include a nano-column, a width or a cross-section of which has a diameter having sub-wavelength dimension. The sub-wavelength refers to a wavelength that is less than a wavelength band of the light condensed by the nano-photonic microlens array. When the incident light is a visible ray, the cross-sectional diameter of the nano-structure NP may be less than, for example, 400 nm, 300 nm, or 200 nm. A height of the nano-structure NP may be about 300 nm to about 1500 nm, which is greater than the cross-sectional diameter of the nano-structure.

2 3 3 4 2 3 4 2 3 The nano-structures NP may include a material having a relatively higher refractive index as compared with a peripheral material and having a relatively lower absorbent ratio in the visible ray band. For example, the nano-structures NP may include c-Si, p-Si, a-Si and a Group III-V compound semiconductor (GaP, GaN, GaAs etc.), SiC, TiO, SiN, ZnS, ZnSe, SiN, and/or a combination thereof. Periphery of the nano-structures NP may be filled with a dielectric material DL having a relatively lower refractive index as compared with the nano-structures NP and have a relatively low absorbent ratio in the visible ray band. For example, the periphery of the nano-structures NP may be filled with siloxane-based spin on glass (SOG), SiO, SiN, AlO, air, etc.

The refractive index of a high-refractive index nano-structures NP may be about 2.0 or greater with respect to the light of about 630 nm wavelength, and the refractive index of a low-refractive index dielectric material DL may be about 1.0 to about 2.0 or less with respect to the light of about 630 nm wavelength. Also, a difference between the refractive index of the nano-structures NP and the refractive index of the dielectric material DL may be about 0.5 or greater. The nano-structures NP having a difference in a refractive index from the refractive index of the peripheral material may change the phase of light that passes through the nano-structures NP. This is caused by phase delay that occurs due to the shape dimension of the sub wavelength of the nanostructures NP, and a degree at which the phase is delayed, may be determined by a detailed shape dimension and arrangement shape of the nanostructures NP.

131 132 133 134 131 132 133 134 131 132 133 134 131 132 133 134 131 132 133 134 131 132 133 134 The first to fourth nano-photonic microlenses,,, andmay each have a nano-pattern structure in which the plurality of nano-structures NP are arranged similarly. For example, each of the first to fourth nano-photonic microlenses,,, andmay have the same number of nano-structures NP. Also, the plurality of nano-structures NP may be arranged at the same positions respectively in the first to fourth nano-photonic microlenses,,, and. From among the plurality of nano-structures NP arranged in each of the first to fourth nano-photonic microlenses,,, and, the nano-structure NP arranged at a center portion in each of the first to fourth nano-photonic microlenses,,, andmay have the largest width or largest diameter, and then, the widths or diameters of the nano-structures NP may be reduced away from the center portion in each of the first to fourth nano-photonic microlenses,,, and.

131 132 133 134 131 132 133 134 131 132 133 134 133 132 131 134 133 132 The widths or diameters of the nano-structures NP in the first to fourth nano-photonic microlenses,,, andmay be different from one another in order for the first to fourth nano-photonic microlenses,,, andto condense the light of different wavelength bands to corresponding pixels. For example, from among the nano-structures NP arranged respectively on the center portions of the first to fourth nano-photonic microlenses,,, and, the nano-structure NP at the center portion of the third nano-photonic microlenscondensing the red light may have the largest width or diameter, and the nano-structure NP at the center portion of the second nano-photonic microlenscondensing the blue light may have the smallest width or diameter. The widths or diameters of the nano-structures NP arranged at the center portions of the first and fourth nano-photonic microlensesandcondensing the green light may be less than the width or diameter of the nano-structure NP arranged at the center portion of the third nano-photonic microlensand may be greater than the width or diameter of the nano-structure NP arranged at the center portion of the second nano-photonic microlens.

6 FIG. 5 FIG. 6 FIG. 6 FIG. 6 FIG. 5 FIG. 1 2 3 4 131 132 133 134 is a plan view showing a nano-pattern structure of one nano-photonic microlens in the nano-photonic microlens array of. Also,shows an example of relative positions of the nano-structures NP with respect to the first to fourth photosensitive cells c, c, c, and cin the pixel corresponding to the nano-photonic microlens. The nano-structures NP having the same widths or diameters inare represented by the same number, and the number representing the nano-structure NP increases as the width or diameter of the nano-structure NP is reduced. The principle of the nano-pattern structure of the nano-photonic microlenses shown inmay be applied to the first to fourth nano-photonic microlenses,,, andshown in.

6 FIG. 1 1 1 Referring to, the plurality of nano-structures may be symmetrically arranged based on a first nano-structurehaving the largest width or diameter in one nano-photonic microlens. The first nano-structuremay be arranged at the center portion of the nano-photonic microlens. Also, the first nano-structurearranged at the center portion of the nano-photonic microlens may be arranged facing, in a vertical direction, a cross point X between the isolation DTI extending in the first direction (X-direction) and the isolation DTI extending in the second direction (Y-direction) in the pixel corresponding to the nano-photonic microlens.

2 1 1 3 2 2 4 3 According to an example embodiment, a nano-structure that is farther away from the center portion of the nano-photonic microlens may have less width or diameter. For example, a plurality of second nano-structureshaving smaller dimensions than that of the first nano-structuremay be arranged to surround the first nano-structure. In addition, a plurality of third nano-structureshaving smaller dimensions than those of the second nano-structuresmay be arranged on the outer sides of the second nano-structures. A plurality of fourth nano-structureshaving smaller dimensions than those of the third nano-structuresmay be arranged near apexes of the nano-photonic microlens. That is, according to an example embodiment, the farther a nano-structure is away from the center portion of the nano-photonic microlens, the smaller the dimensions of the nano-structure.

6 FIG. 6 FIG. 1 1 131 132 133 134 1 1 132 1 shows that the nano-photonic microlens includes total 25 nano-structures having four different widths or diameters, but one or more example embodiments are not limited thereto. Also,shows that the nano-photonic microlens includes one largest first nano-structure, but there may be a plurality of first nano-structureshaving the largest dimensions in the nano-photonic microlens. Alternatively, in some of the first to fourth nano-photonic microlenses,,, and, there may be a plurality of first nano-structures, and in some other nano-photonic microlenses, there may be only one first nano-structure. For example, the second nano-photonic microlenscondensing the blue light may include nine first nano-structureshaving the same widths or diameters at the center portion thereof. The dimensions, number, and kinds of the nano-structures arranged in the nano-photonic microlens may be selected taking into account various elements such as optical characteristics of an objective lens of a camera, a pixel size, a size and sensitivity of the photosensitive cell, a light condensing efficiency, auto-focusing performance, a crosstalk, etc.

According to the example embodiment, the plurality of nano-structures in the nano-photonic microlens may be arranged in the form of a two-dimensional array in a diagonal direction between the first direction (X-direction) and the second direction (Y-direction). In other words, the plurality of nano-structures may be arranged in the form of the two-dimensional grating array that is inclined in the diagonal direction. Therefore, a figure formed by connecting four adjacent nano-structures so that another nano-structure may not exist therein may have a rectangular shape inclined in the diagonal direction of the nano-photonic microlens or the pixel. When each of the pixels or the nano-photonic microlenses has a square shape, an angle in which the arrangement of the plurality of nano-structures is inclined may be about 45°. When each of the pixels or the nano-photonic microlenses is not a square, the angle in which the arrangement of the plurality of nano-structure is inclined may vary depending on an aspect ratio of each pixel or each nano-photonic microlens and may be in a range of about 30° to about 60°.

4 3 2 1 2 3 4 3 2 2 2 3 In this case, the plurality of nano-structures may be arranged at constant period or interval along two diagonal directions in each pixel or each nano-photonic microlens. In other words, the period or interval between the plurality of nano-structures arranged in a first diagonal direction may be equal to the period or interval between the plurality of nano-structures arranged in a second diagonal direction that crosses the first diagonal direction. Also, the period or interval between the plurality of nano-structures may be consistent on all the cross-sections in the diagonal direction and in the direction parallel to the diagonal line. For example, the period or interval among the plurality of nano-structures (,,,,,,) arranged along the diagonal direction passing the center of the nano-photonic microlens may be equal to the period or interval among the plurality of nano-structures (,,,,) arranged in the direction that is parallel to the diagonal direction without passing the center of the nano-photonic microlens.

1 2 2 2 1 1 In an example, an interval dbetween two adjacent nano-structures in the first direction (X-direction) or the second direction (Y-direction) may be greater than an interval dbetween two adjacent nano-structures in the diagonal direction. Therefore, the arrangement period of the plurality of nano-structures arranged in the first direction (X-direction) or the second direction (Y-direction) may be greater than the arrangement period of the plurality of nano-structures arranged in the diagonal direction. In this case, the second nano-structuremay be arranged so as not to face the isolation DTI in the vertical direction because the second nano-structurethat is closest to the first nano-structurearranged at the center of each nano-photonic microlens is located diagonally with respect to the first nano-structure.

6 FIG. 6 FIG. 1 2 1 2 1 1 2 1 2 1 2 1 shows that three adjacent nano-structures are arranged in the form of isosceles triangle, but the three adjacent nano-structures may be arranged in the form of a regular triangle. For example, the first nano-structure, the second nano-structureadjacent to the first nano-structurein the first direction (X-direction), and the second nano-structureadjacent to the first nano-structurein the diagonal direction may be arranged in the form of an isosceles triangle having the largest bottom side, as shown in. However, one or more example embodiments are not limited thereto, and in another example, the first nano-structure, the second nano-structureadjacent to the first nano-structurein the first direction (X-direction), and the second nano-structureadjacent to the first nano-structurein the diagonal direction may be arranged in the form of the regular triangle. In this case, the interval dbetween two adjacent nano-structures in the first direction (X-direction) or the second direction (Y-direction) may be equal to the interval dbetween two adjacent nano-structures in the diagonal direction, and the arrangement period of the plurality of nano-structures arranged in the first direction (X-direction) or the second direction (Y-direction) may be equal to the arrangement period of the plurality of nano-structures arranged in the diagonal direction.

2 3 2 1 3 2 Also, from among the plurality of nano-structures arranged in each of the nano-photonic microlenses, a straight line connecting at least three nano-structures having the same widths or diameters may be arranged in parallel to the diagonal direction. For example, a straight line connecting three second nano-structuresor a straight line connecting three third nano-structuresmay be in parallel to the diagonal direction. Accordingly, the nano-structures having the same widths or diameters may be arranged to surround other nano-structures in the form of a rectangular shape inclined in the diagonal direction. For example, the second nano-structuresare arranged in the form of a rectangular shape that is inclined in the diagonal direction while surrounding the first nano-structures, and the third nano-structuresmay be arranged in the form of a rectangular shape that is inclined in the diagonal direction while surrounding the second nano-structures.

7 FIG. 6 FIG. 7 FIG. 7 FIG. 7 FIG. is a diagram showing an example of a phase profile of a transmitted light immediately after passing through the nano-photonic microlens ofin the form of contours. In, one rectangle is obtained by connecting points having the same phase. Referring to, immediately after passing through the nano-photonic microlens, that is, at the lower surface of the nano-photonic microlens, the transmitted light may have a phase profile formed as a rectangle inclined in the diagonal direction with respect to the nano-photonic microlens or the pixel. In, the innermost rectangle at the center of the nano-photonic microlens represents the largest phase, and the rectangle away from the center portion represents smaller phase than that of inside rectangle. Therefore, the phase of the transmitted light immediately after passing through the nano-photonic microlens is the largest at the center portion of the nano-photonic microlens and then may be gradually decreased toward the outer side. In addition, the phase of the transmitted light may be the smallest around four apexes of the nano-photonic microlens. In particular, a figure obtained by connecting the points having the same phase of transmitted light may have a rectangular shape that is inclined in the diagonal direction with respect to the nano-photonic microlens or the pixel.

8 FIG.A 6 FIG. 8 FIG.B 6 FIG. 8 FIG.C 6 FIG. is a diagram showing an example of a phase profile of transmitted light on a cross-section of a nano-photonic microlens taken along line A-A′ of,is a diagram showing an example of a phase profile of the transmitted light on a cross-section of the nano-photonic microlens taken along line B-B′ of, andis a diagram showing an example of a phase profile of the transmitted light on a cross-section of a nano-photonic microlens taken along line C-C′ of.

8 8 FIGS.A toC 8 8 FIGS.A toC Referring to, the phase profile of the transmitted light immediately after passing through the nano-photonic microlens may have a convex shape.show the phase profile formed in a convex curve shape for convenience of description, but the transmitted light immediately after passing through the nano-photonic microlens may have a phase profile formed in a convex stair shape.

8 FIG.A 8 FIG.B 1 2 3 4 2 4 Referring to, on a cross-section passing the center portion of the nano-photonic microlens in the first direction (X-direction) (that is, cross-section taken along line A-A′), the phase of light after passing through the nano-photonic microlens may have a maximum value Φat the center and a minimum value Φat opposite edges. Also, referring to, on a cross-section passing the edge of the nano-photonic microlens in the first direction (X-direction) (that is, cross-section taken along line B-B′), the phase of light after passing through the nano-photonic microlens may have a maximum value Φat the center and may have a minimum value Φat opposite edges. The minimum value Φof the phase of light after passing through the nano-photonic microlens on the cross-section passing the center portion of the nano-photonic microlens in the first direction (X-direction) may be greater than the minimum value Φof the phase of the light after passing through the nano-photonic microlens on the cross-section passing the edge of the nano-photonic microlens.

8 FIG.C 1 4 Referring to, on the cross-section in the diagonal direction of the nano-photonic microlens (that is, cross-section taken along line C-C′), the phase of light after passing through the nano-photonic microlens may have a maximum value Φat the center and may have a minimum value Φat the opposite edges. Therefore, the maximum value of the phase of light after passing through the nano-photonic microlens, on the cross-section in the diagonal direction, may be equal to the maximum value of the phase of light after passing through the nano-photonic microlens on the cross-section passing the center portion of the nano-photonic microlens. Also, the minimum value of the phase of light after passing through the nano-photonic microlens, on the cross-section in the diagonal direction, may be equal to the minimum value of the phase of light after passing through the nano-photonic microlens on the cross-section passing the edges of the nano-photonic microlens.

As described above, each of the nano-photonic microlenses includes a plurality of nano-structures that are arranged such that the light after passing through each of the nano-photonic microlenses has a phase profile that is convex. Then, each of the nano-photonic microlenses may condense the incident light to the corresponding pixel.

131 132 133 134 131 132 133 134 131 132 133 134 131 132 133 134 5 FIG. 7 8 8 FIGS.andA toC 5 FIG. For example, the plurality of nano-structures NP arranged in each of the first to fourth nano-photonic microlenses,,, andshown inmay be arranged so as to implement the phase profiles shown in. In other words, the plurality of nano-structures NP may be arranged so that the light passing through the center portion in each of the first to fourth nano-photonic microlenses,,, andhas the largest phase and the phase of the transmitted light is gradually decreased away from the center portion in each of the first to fourth nano-photonic microlenses,,, and. In general, the phase of the light after passing through each of the nano-structures NP may be in proportional to the width or diameter of the nano-structure NP. Accordingly,illustrates that the width or diameter of the nano-structure NP arranged at the center portion of each of the first to fourth nano-photonic microlenses,,, andis the largest.

7 8 8 FIGS.andA toC 131 132 133 134 131 132 133 134 131 132 133 134 131 132 133 134 However, the nano-structures NP arranged in the region having a relatively small phase delay do not necessarily have relatively smaller diameters. In the phase profiles shown in, a value of phase delay is indicated by a remainder value after subtracting a multiple of 2π. For example, when a phase delay in a certain region is 3π, the phase delay is optically the same as the remaining π after removing 2π. Therefore, when the diameter of the nano-structure NP is so small and is difficult to be manufactured, the width or diameter of the nano-structure NP may be selected so as to implement the delay phase increased by 2π. For example, when the width or diameter of the nano-structure NP for achieving the phase delay of 0.5π is too small, the width or diameter of the nano-structure NP may be selected so as to achieve the phase delay of 2.5π. Therefore, in another example, the width or diameter of the nano-structure NP arranged around the apex of each of the first to fourth nano-photonic microlenses,,, andmay be the largest, and the width or diameter of the nano-structure NP arranged at the center in each of the first to fourth nano-photonic microlenses,,, andmay be the second largest. Alternatively, the width or diameter of the nano-structure NP arranged at the center in each of the first to fourth nano-photonic microlenses,,, andmay be the smallest and the width or diameter of the nano-structure NP may be increased away from the center in each of the first to fourth nano-photonic microlenses,,, and.

9 FIG. 6 FIG. 9 FIG. 1 2 3 4 1 2 3 4 is a plan view showing an example of a distribution of a focusing spot formed on a pixel by the nano-photonic microlens of. Referring to, a focusing spot FS formed by the nano-photonic microlenses may be mainly distributed on the center portion of the pixel. In other words, the focusing spot FS may be located at the center of 2×2 array including four photosensitive cells c, c, c, and c. Therefore, the focusing spot FS may be formed on a crossing point between two isolations DTI. Also, the focusing spot FS may have a rectangular shape that is similar to the shape of the pixel. In particular, the focusing spot FS may have a rectangular shape that is parallel to the rectangular shape of the pixel. Consequently, the focusing spot FS may spread to the center portion in each of the four photosensitive cells c, c, c, and cin the pixel.

10 FIG. 10 FIG. 10 10 11 12 13 14 10 130 10 is a plan view schematically showing a structure of a nano-photonic microlens arrayaccording to a comparative example. Referring to, in the nano-photonic microlens arrayaccording to the comparative example, each of a plurality of nano-photonic microlenses,,, andmay include the nano-structures NP that are regularly arranged in the first direction (X-direction) and the second direction (Y-direction). Therefore, in the nano-photonic microlens arrayaccording to the comparative example, the plurality of nano-structures NP are periodically arranged in a direction parallel to the direction in which the isolation is extended. As a result, the nano-structures NP of the nano-photonic microlens arrayaccording to the example embodiment and the nano-structures NP of the nano-photonic microlens arrayaccording to the comparative example may be arranged by being rotated by an angle in the diagonal direction with respect to each other.

11 FIG. 10 FIG. 11 FIG. 10 1 1 1 1 1 2 3 4 is a plan view showing an example of a distribution of focusing spots formed on pixels by one nano-photonic microlens in the nano-photonic microlens arrayof. Referring to, a focusing spot FSformed by the nano-photonic microlens according to the comparative example may be mainly distributed on the center portion of the pixel. In particular, the focusing spot FSis inclined with respect to the rectangular shape of the pixel in the diagonal direction. Also, the focusing spot FSmay have four concave sides. As a result, according to the comparative example, the focusing spot FSrarely spreads to the center portion in each of the four photosensitive cells c, c, c, and cin the pixel.

9 FIG. 11 FIG. 1 1 130 1 1 2 3 4 1 2 3 4 1 2 3 4 1 1 2 3 4 130 When the distribution of the focusing spot FS shown inis compared with the distribution of the focusing spot FSshown in, an overlapping area between the focusing spot FSaccording to the comparative example and the isolation DTI is greater than an overlapping area between the focusing spot FS according to the example embodiment and the isolation DTI. Therefore, when the nano-photonic microlens arrayaccording to the example embodiment is used, light loss may be reduced as compared with the comparative example. Also, the focusing spot FSaccording to the comparative example rarely spreads to the center portions of the four photosensitive cells c, c, c, and cin the pixel, but the focusing spot FS according to the example embodiment may spread to the center portions of the four photosensitive cells c, c, c, and cin the pixel. That is, the distribution area of the focusing spot FS in the photosensitive cells c, c, c, and cmay be greater than that of the focusing spot FSaccording to the comparative example. As such, an intensity of an output signal from each of the photosensitive cells c, c, c, and cmay increase. Therefore, when the nano-photonic microlens arrayaccording to the example embodiment is used, the crosstalk between adjacent photosensitive cells may be reduced, and accuracy of the auto-focusing function that is implemented by comparing the output signals from the adjacent photosensitive cells may be improved.

12 FIG. 5 FIG. 10 FIG. 12 FIG. 12 FIG. is a graph for comparing the quantum efficiency of an image sensor including the nano-photonic microlens array ofwith that of an image sensor including the nano-photonic microlens array ofaccording to the comparative example. In, graphs indicated as B′, G′, and R′ represent a quantum efficiency of the image sensor according to the comparative example with respect to the blue light, green light, and red light, and graphs indicated as B, G, and R represent a quantum efficiency of the image sensor according to the example embodiment with respect to the blue light, green light, and red light. Referring to, the image sensor according to the example embodiment may have an improved quantum efficiency in the blue light region as compared with the image sensor according to the comparative example, and may have entirely reduced crosstalk. Accordingly, the auto-focusing function of the phase-detection auto-focusing method may be improved.

13 13 FIGS.A andB 3 5 6 FIGS.,, and 13 FIG.A 13 FIG.B 130 are plan views showing a structure of one nano-photonic microlens in a nano-photonic microlens array according to another example embodiment. In, the nano-structure NP in the nano-photonic microlens arrayhas a circular column shape, but the nano-structures NP may have various different shapes. For example, as shown in, the nano-structure NP may have a polygonal column shape such as a rectangular column. Also, as shown in, the nano-structure may have a polygonal container shape such as a rectangular container shape, or a cylindrical shape. The shape of the nano-structure NP may be selected taking into account various elements such as optical characteristics of an objective lens of a camera, a pixel size, a size and sensitivity of the photosensitive cell, a light condensing efficiency, an auto-focusing performance, crosstalk, etc.

14 FIG. 14 FIG. 6 FIG. 130 1101 130 1 2 1 1 1 2 2 2 1 2 1 2 1 1 2 is a cross-sectional view schematically showing a structure of a pixel array in an image sensor according to another example embodiment. Referring to, the nano-photonic microlens arrayof a pixel arraymay have a multi-layered structure including two or more layers. For example, the nano-photonic microlens arraymay include a first layer Land a second layer Lstacked on the first layer L. The first layer Lmay include a plurality of first nano-structures NP. The second layer Lmay include a plurality of second nano-structures NP. The plurality of second nano-structures NPmay be stacked on the plurality of first nano-structures NPcorresponding thereto. Widths or diameters of the plurality of second nano-structures NPmay be equal to or different from widths or diameters of the first nano-structures NPcorresponding thereto. For example, the width or diameter of the second nano-structure NPmay be less than the width or diameter of the first nano-structure NPcorresponding thereto. The plurality of first nano-structures NPand the plurality of second nano-structures NPmay be arranged according to the arrangement rule described above with reference to.

15 FIG. 15 FIG. 1102 1102 140 130 140 130 1102 140 130 140 140 140 140 2 3 4 2 3 2 3 4 2 3 is a cross-sectional view schematically showing a structure of a pixel arrayin an image sensor according to another example embodiment. Referring to, a pixel arraymay further include an anti-reflection layeron a light-incident surface of the nano-photonic microlens array. The anti-reflection layermay reduce the light reflected by the upper surface of the nano-photonic microlens array, and thus, may improve the light-utilization efficiency of the pixel array. The anti-reflection layermay include a single layer formed of a material having a refractive index that is different from that of the material included in the nano-structure of the nano-photonic microlens array, for example, one selected from SiO, SiN, and AlO. The anti-reflection layermay have a thickness of about 80 nm to about 120 nm. Alternatively, the anti-reflection layermay have a multi-layered structure in which different dielectric materials are alternately stacked. For example, the anti-reflection layermay be formed by alternately stacking two or three of SiO, SiN, and AlO. Alternatively, the anti-reflection layermay include various patterns for anti-reflection.

1102 1102 220 110 130 220 221 111 222 112 220 113 114 15 FIG. Also, the pixel arraymay include an inorganic color filter, instead of an organic color filter. For example, the pixel arraymay include an inorganic color filter layerbetween the sensor substrateand the nano-photonic microlens array. The inorganic color filter layermay include a first inorganic color filterarranged on the first pixel, and a second inorganic color filterarranged on the second pixel. Although not shown in, the inorganic color filter layermay further include a third inorganic color filter arranged on the third pixel, and a fourth inorganic color filter arranged on the fourth pixel.

221 221 222 222 221 222 220 220 221 222 221 222 a a a a a a a a a. The first inorganic color filtermay include, for example, a plurality of first nano-patternsthat are configured to transmit green light and absorb or reflect the light of other wavelength bands. The second inorganic color filtermay include, for example, a plurality of second nano-patternsthat are configured to transmit blue light and absorb or reflect the light of other wavelength bands. The first nano-patternsmay be arranged to have less width, interval, cycle, etc. than wavelength of the wavelength band of the green light, and the second nano-patternsmay be arranged to have less width, interval, cycle, etc. than wavelength of the wavelength band of the blue light. Also, the third inorganic color filter may include a plurality of third nano-patterns that are configured to transmit red light and absorb or reflect the light of other wavelength bands, and the fourth inorganic color filter may include a plurality of fourth nano-patterns that are configured to transmit green light and absorb or reflect the light of other wavelength bands. Also, the inorganic color filter layermay further include a dielectric materialthat surrounds the periphery of the first nano-patternsand the periphery of the second nano-patternsand has a refractive index less than that of the first nano-patternsand the refractive index of the second nano-patterns

16 FIG. 16 FIG. 16 FIG. 1103 1103 120 220 220 120 120 220 121 221 122 222 is a cross-sectional view schematically showing a structure of a pixel arrayin an image sensor according to another example embodiment. Referring to, the pixel arraymay include the color filter layerincluding a plurality of organic color filters and the inorganic color filter layerincluding a plurality of inorganic color filters.shows that the inorganic color filter layeris arranged on the color filter layer, but the color filter layermay be arranged on the inorganic color filter layer. In this case, the first color filterand the first inorganic color filtermay form a first organic/inorganic hybrid color filter along with each other. Also, the second color filterand the second inorganic color filtermay form a second organic/inorganic hybrid color filter along with each other.

17 FIG. 17 FIG. 1104 1100 210 120 210 230 120 is a perspective view schematically showing a structure of a pixel arrayin an image sensor according to another example embodiment. Referring to, the pixel arraymay include a sensor substrate, a color filter layeron the sensor substrate, and a nano-photonic microlens arrayon the color filter layer.

18 FIG. 17 FIG. 18 FIG. 18 FIG. 210 210 211 212 213 214 211 214 212 213 211 212 213 214 211 212 213 214 is a plan view schematically showing a structure of the sensor substratein the pixel array of. Referring to, the sensor substratemay include a first pixel, a second pixel, a third pixel, and a fourth pixelthat are arranged in the Bayer pattern type. For example, the first and fourth pixelsandmay be green pixels sensing green light, the second pixelmay be a blue pixel sensing blue light, and the third pixelmay be a red pixel sensing red light. Althoughonly shows one of each of the first to fourth pixels,,, and, a plurality of first to fourth pixels,,, andmay be two-dimensionally arranged in the Bayer pattern type.

211 212 213 214 211 211 211 211 211 212 212 212 212 212 213 213 213 213 213 214 214 214 214 214 211 211 211 211 212 212 212 212 213 213 213 213 214 214 214 214 1 2 3 4 211 212 213 214 The first to fourth pixels,,, andmay each include four sub-pixels that are independent from one another and arranged in 2×2 array. For example, the first pixelmay include a first sub-pixelA, a second sub-pixelB, a third sub-pixelC, and a fourth sub-pixelD. Also, the second pixelmay include a first sub-pixelA, a second sub-pixelB, a third sub-pixelC, and a fourth sub-pixelD, the third pixelmay include a first sub-pixelA, a second sub-pixelB, a third sub-pixelC, and a fourth sub-pixelD, and the fourth pixelmay include a first sub-pixelA, a second sub-pixelB, a third sub-pixelC, and a fourth sub-pixelD. Also, each of the plurality of sub-pixelsA,B,C,D,A,B,C,D,A,B,C,D,A,B,C, andD may include a plurality of independent photosensitive cells that are arranged in 2×2 array, for example, first to fourth photosensitive cells c, c, c, and c. Each of the first to fourth pixels,,, andmay include four sub-pixels and 16 photosensitive cells.

17 FIG. 121 211 122 212 123 213 124 214 121 211 211 211 211 211 122 212 212 212 212 212 123 213 213 213 213 213 124 214 214 214 214 214 Referring back to, the first color filteris arranged facing the first pixelcorresponding thereto, the second color filteris arranged facing the second pixelcorresponding thereto, the third color filteris arranged facing the third pixelcorresponding thereto, and the fourth color filteris arranged facing the fourth pixelcorresponding thereto. Therefore, the first color filtermay face the first to fourth sub-pixelsA,B,C, andD of the first pixel, the second color filtermay face the first to fourth sub-pixelsA,B,C, andD of the second pixel, the third color filtermay face the first to fourth sub-pixelsA,B,C, andD of the third pixel, and the fourth color filtermay face the first to fourth sub-pixelsA,B,C, andD of the fourth pixel.

19 FIG. 17 FIG. 19 FIG. 230 230 230 231 211 211 211 211 211 232 212 212 212 212 212 233 213 213 213 213 213 234 214 214 214 214 214 231 211 232 212 233 213 234 214 is a plan view schematically showing a structure of the nano-photonic microlens arrayaccording to an example embodiment of. Referring to, the nano-photonic microlens arraymay include a plurality of nano-photonic microlenses that correspond to the plurality of sub-pixels in one-to-one correspondence. For example, the nano-photonic microlens arraymay include a plurality of first nano-photonic microlensesthat are arranged to respectively face the first to fourth sub-pixelsA,B,C, andD of the first pixel, a plurality of second nano-photonic microlensesthat are arranged to respectively face the first to fourth sub-pixelsA,B,C, andD of the second pixel, a plurality of third nano-photonic microlensesthat are arranged to respectively face the first to fourth sub-pixelsA,B,C, andD of the third pixel, and a plurality of fourth nano-photonic microlensesthat are arranged to respectively face the first to fourth sub-pixelsA,B,C, andD of the fourth pixel. Therefore, four first nano-photonic microlensesthat are arranged in 2×2 array are arranged with respect to one first pixel, four second nano-photonic microlensesthat are arranged in 2×2 array are arranged with respect to one second pixel, four third nano-photonic microlensesthat are arranged in 2×2 array are arranged with respect to one third pixel, and four fourth nano-photonic microlensesthat are arranged in 2×2 array are arranged with respect to one fourth pixel.

231 1 2 3 4 211 211 211 211 211 232 1 2 3 4 212 212 212 212 212 233 1 2 3 4 213 213 213 213 213 234 1 2 3 4 214 214 214 214 214 Also, each of the four first nano-photonic microlensesmay be arranged to face the first to fourth photosensitive cells c, c, c, and cof one corresponding sub-pixel from among the first to fourth sub-pixelsA,B,C, andD of the first pixel, each of the four second nano-photonic microlensesmay be arranged to face the first to fourth photosensitive cells c, c, c, and cof one corresponding sub-pixel from among the first to fourth sub-pixelsA,B,C, andD of the second pixel, each of the four third nano-photonic microlensesmay be arranged to face the first to fourth photosensitive cells c, c, c, and cof one corresponding sub-pixel from among the first to fourth sub-pixelsA,B,C, andD of the third pixel, and each of the four fourth nano-photonic microlensesmay be arranged to face the first to fourth photosensitive cells c, c, c, and cof one corresponding sub-pixel from among the first to fourth sub-pixelsA,B,C, andD of the fourth pixel.

231 131 232 132 233 133 234 134 5 FIG. 5 FIG. 5 FIG. 5 FIG. Each of the four first nano-photonic microlensesmay have the same nano-pattern structure as that of the first nano-photonic microlensshown in, each of the four second nano-photonic microlensesmay have the same nano-pattern structure as that of the second nano-photonic microlensshown in, each of the four third nano-photonic microlensesmay have the same nano-pattern structure as that of the third nano-photonic microlensshown in, and each of the four fourth nano-photonic microlensesmay have the same nano-pattern structure as that of the fourth nano-photonic microlensshown in.

231 211 211 211 211 211 231 1 2 3 4 232 212 212 212 212 212 232 1 2 3 4 233 213 213 213 213 213 233 1 2 3 4 234 214 214 214 214 214 234 1 2 3 4 Therefore, each of the four first nano-photonic microlensesmay be configured to condense the incident light to one corresponding sub-pixel from among the first to fourth sub-pixelsA,B,C, andD of the first pixel. Then, the focusing spot formed by each of the four first nano-photonic microlensesmay be located at the center of 2×2 array including the first to fourth photosensitive cells c, c, c, and cof the corresponding sub-pixel. Also, each of four second nano-photonic microlensesmay be provided to condense the incident light to corresponding sub-pixel from among the first to fourth sub-pixelsA,B,C, andD of the second pixel. The focusing spot formed by each of the four second nano-photonic microlensesmay be located at the center of 2×2 array including the first to fourth photosensitive cells c, c, c, and cof the corresponding sub-pixel. Each of four third nano-photonic microlensesmay be provided to condense the incident light to corresponding sub-pixel from among the first to fourth sub-pixelsA,B,C, andD of the third pixel. The focusing spot formed by each of the four third nano-photonic microlensesmay be located at the center of 2×2 array including the first to fourth photosensitive cells c, c, c, and cof the corresponding sub-pixel. Each of four fourth nano-photonic microlensesmay be provided to condense the incident light to corresponding sub-pixel from among the first to fourth sub-pixelsA,B,C, andD of the fourth pixel. The focusing spot formed by each of the four fourth nano-photonic microlensesmay be located at the center of 2×2 array including the first to fourth photosensitive cells c, c, c, and cof the corresponding sub-pixel.

20 FIG. 19 FIG. 18 FIG. 10 FIG. 10 FIG. 10 FIG. 10 FIG. 210 11 211 211 211 211 211 12 212 212 212 212 212 13 213 213 213 213 213 14 214 214 214 214 214 is a graph for comparing the quantum efficiency of an image sensor including the nano-photonic microlens array ofaccording to the example embodiment with the quantum efficiency of an image sensor according to a comparative example. The image sensor according to the comparative example includes the sensor substrateshown in. In the image sensor, the first nano-photonic microlensshown inis arranged with respect to each of the plurality of sub-pixelsA,B,C, andD in the first pixel, the second nano-photonic microlensshown inis arranged with respect to the first to fourth sub-pixelsA,B,C, andD of the second pixel, the third nano-photonic microlensshown inis arranged with respect to each of the first to fourth sub-pixelsA,B,C, andD of the third pixel, and the fourth nano-photonic microlensshown inis arranged with respect to each of the first to fourth sub-pixelsA,B,C, andD of the fourth pixel.

20 FIG. 20 FIG. In, graphs indicated as B′, G′, and R′ represent a quantum efficiency of the image sensor according to the comparative example with respect to the blue light, green light, and red light, and graphs indicated as B, G, and R represent a quantum efficiency of the image sensor according to the example embodiment with respect to the blue light, green light, and red light. Referring to, the image sensor according to the example embodiment may have an improved quantum efficiency in the blue light region as compared with the image sensor according to the comparative example, and may have entirely reduced crosstalk. Therefore, the accuracy of the auto-focusing function implemented by comparing output signals from adjacent photosensitive cells may be improved.

The image sensor according to the example embodiment may form a camera module along with a module lens of various functions and may be utilized in various electronic devices.

21 FIG. 21 FIG. 1 1000 0 1 2 98 4 8 99 1 4 8 1 20 30 50 55 60 70 76 77 79 80 88 89 90 96 97 1 60 76 60 is a block diagram showing an example of an electronic apparatus EDincluding an image sensor. Referring to, in a network environment ED, the electronic apparatus EDmay communicate with another electronic apparatus EDvia a first network ED(short-range wireless communication network, etc.), or may communicate with another electronic apparatus EDand/or a server EDvia a second network ED(long-range wireless communication network, etc.) The electronic apparatus EDmay communicate with the electronic apparatus EDvia the server ED. The electronic apparatus EDmay include a processor ED, a memory ED, an input device ED, a sound output device ED, a display device ED, an audio module ED, a sensor module ED, an interface ED, a haptic module ED, a camera module ED, a power management module ED, a battery ED, a communication module ED, a subscriber identification module ED, and/or an antenna module ED. In the electronic apparatus ED, some (display device ED, etc.) of the elements may be omitted or another element may be added. Some of the elements may be configured as one integrated circuit. For example, the sensor module ED(a fingerprint sensor, an iris sensor, an illuminance sensor, etc.) may be embedded and implemented in the display device ED(display, etc.)

20 1 20 40 20 76 90 32 32 34 20 21 23 21 23 21 The processor EDmay control one or more elements (hardware, software elements, etc.) of the electronic apparatus EDconnected to the processor EDby executing software (program ED, etc.), and may perform various data processes or operations. As a part of the data processing or operations, the processor EDmay load a command and/or data received from another element (sensor module ED, communication module ED, etc.) to a volatile memory ED, may process the command and/or data stored in the volatile memory ED, and may store result data in a non-volatile memory ED. The processor EDmay include a main processor ED(central processing unit, application processor, etc.) and an auxiliary processor ED(graphic processing unit, image signal processor, sensor hub processor, communication processor, etc.) that may be operated independently from or along with the main processor ED. The auxiliary processor EDmay use less power than that of the main processor ED, and may perform specified functions.

23 21 21 21 21 60 76 90 1 23 80 90 The auxiliary processor ED, on behalf of the main processor EDwhile the main processor EDis in an inactive state (sleep state) or along with the main processor EDwhile the main processor EDis in an active state (application executed state), may control functions and/or states related to some (display device ED, sensor module ED, communication module ED, etc.) of the elements in the electronic apparatus ED. The auxiliary processor ED(image signal processor, communication processor, etc.) may be implemented as a part of another element (camera module ED, communication module ED, etc.) that is functionally related thereto.

30 20 76 1 40 30 32 34 The memory EDmay store various data required by the elements (processor ED, sensor module ED, etc.) of the electronic apparatus ED. The data may include, for example, input data and/or output data about software (program ED, etc.) and commands related thereto. The memory EDmay include the volatile memory EDand/or the non-volatile memory ED.

40 30 42 44 46 The program EDmay be stored as software in the memory ED, and may include an operation system ED, middleware ED, and/or an application ED.

50 20 1 1 50 The input device EDmay receive commands and/or data to be used in the elements (processor ED, etc.) of the electronic apparatus ED, from outside (user, etc.) of the electronic apparatus ED. The input device EDmay include a microphone, a mouse, a keyboard, and/or a digital pen (stylus pen).

55 1 55 The sound output device EDmay output a sound signal to outside of the electronic apparatus ED. The sound output device EDmay include a speaker and/or a receiver. The speaker may be used for a general purpose such as multimedia reproduction or record play, and the receiver may be used to receive a call. The receiver may be coupled as a part of the speaker or may be implemented as an independent device.

60 1 60 60 The display device EDmay provide visual information to outside of the electronic apparatus ED. The display device EDmay include a display, a hologram device, or a projector, and a control circuit for controlling the corresponding device. The display device EDmay include a touch circuitry set to sense a touch, and/or a sensor circuit (pressure sensor, etc.) that is set to measure a strength of a force generated by the touch.

70 70 50 55 2 1 The audio module EDmay convert sound into an electrical signal or vice versa. The audio module EDmay acquire sound through the input device ED, or may output sound via the sound output device EDand/or a speaker and/or a headphone of another electronic apparatus (electronic apparatus ED, etc.) connected directly or wirelessly to the electronic apparatus ED.

76 1 76 The sensor module EDmay sense an operating state (power, temperature, etc.) of the electronic apparatus ED, or an outer environmental state (user state, etc.), and may generate an electrical signal and/or data value corresponding to the sensed state. The sensor module EDmay include a gesture sensor, a gyro-sensor, a pressure sensor, a magnetic sensor, an acceleration sensor, a grip sensor, a proximity sensor, a color sensor, an infrared (IR) ray sensor, a vivo sensor, a temperature sensor, a humidity sensor, and/or an illuminance sensor.

77 1 2 77 The interface EDmay support one or more designated protocols that may be used in order for the electronic apparatus EDto be directly or wirelessly connected to another electronic apparatus (electronic apparatus ED, etc.) The interface EDmay include a high-definition multimedia interface (HDMI), a universal serial bus (USB) interface, an SD card interface, and/or an audio interface.

78 1 2 78 The connection terminal EDmay include a connector by which the electronic apparatus EDmay be physically connected to another electronic apparatus (electronic apparatus ED, etc.). The connection terminal EDmay include an HDMI connector, a USB connector, an SD card connector, and/or an audio connector (headphone connector, etc.).

79 79 The haptic module EDmay convert the electrical signal into a mechanical stimulation (vibration, motion, etc.) or an electric stimulation that the user may sense through a tactile or motion sensation. The haptic module EDmay include a motor, a piezoelectric device, and/or an electric stimulus device.

80 80 1000 80 1 FIG. The camera module EDmay capture a still image and a video. The camera module EDmay include a lens assembly including one or more lenses, the image sensorof, image signal processors, and/or flashes. The lens assembly included in the camera module EDmay collect light emitted from an object that is an object to be captured.

88 1 88 The power management module EDmay manage the power supplied to the electronic apparatus ED. The power management module EDmay be implemented as a part of a power management integrated circuit (PMIC).

89 1 89 The battery EDmay supply electric power to components of the electronic apparatus ED. The battery EDmay include a primary battery that is not rechargeable, a secondary battery that is rechargeable, and/or a fuel cell.

90 1 2 4 8 90 20 90 92 94 9 99 92 1 98 99 96 The communication module EDmay support the establishment of a direct (wired) communication channel and/or a wireless communication channel between the electronic apparatus EDand another electronic apparatus (electronic apparatus ED, electronic apparatus ED, server ED, etc.), and execution of communication through the established communication channel. The communication module EDmay be operated independently from the processor ED(application processor, etc.), and may include one or more communication processors that support the direct communication and/or the wireless communication. The communication module EDmay include a wireless communication module ED(cellular communication module, a short-range wireless communication module, a global navigation satellite system (GNSS) communication module) and/or a wired communication module ED(local area network (LAN) communication module, a power line communication module, etc.). From among the communication modules, a corresponding communication module may communicate with another electronic apparatus via a first network ED(short-range communication network such as Bluetooth, WiFi direct, or infrared data association (IrDA)) or a second network ED(long-range communication network such as a cellular network, Internet, or computer network (LAN, WAN, etc.)). Such above various kinds of communication modules may be integrated as one element (single chip, etc.) or may be implemented as a plurality of elements (a plurality of chips) separately from one another. The wireless communication module EDmay identify and authenticate the electronic apparatus EDin a communication network such as the first network EDand/or the second network EDby using subscriber information (international mobile subscriber identifier (IMSI), etc.) stored in the subscriber identification module ED.

97 97 97 98 99 90 90 97 The antenna module EDmay transmit or receive the signal and/or power to/from outside (another electronic apparatus, etc.). An antenna may include a radiator formed as a conductive pattern formed on a substrate (PCB, etc.). The antenna module EDmay include one or more antennas. When the antenna module EDincludes a plurality of antennas, from among the plurality of antennas, an antenna that is suitable for the communication type used in the communication network such as the first network EDand/or the second network EDmay be selected by the communication module ED. The signal and/or the power may be transmitted between the communication module EDand another electronic apparatus via the selected antenna. Another component (RFIC, etc.) other than the antenna may be included as a part of the antenna module ED.

Some of the elements may be connected to one another via the communication method among the peripheral devices (bus, general purpose input and output (GPIO), serial peripheral interface (SPI), mobile industry processor interface (MIPI), etc.) and may exchange signals (commands, data, etc.).

1 4 8 99 2 4 1 1 2 4 8 1 1 1 The command or data may be transmitted or received between the electronic apparatus EDand the external electronic apparatus EDvia the server EDconnected to the second network ED. Other electronic apparatuses EDand EDmay be the devices that are the same as or different kinds from the electronic apparatus ED. All or some of the operations executed in the electronic apparatus EDmay be executed in one or more devices among the other electronic apparatuses ED, ED, and ED. For example, when the electronic apparatus EDhas to perform a certain function or service, the electronic apparatus EDmay request one or more other electronic apparatuses to perform some or entire function or service, instead of executing the function or service by itself. One or more electronic apparatuses receiving the request execute an additional function or service related to the request and may transfer a result of the execution to the electronic apparatus ED. To do this, for example, a cloud computing, a distributed computing, or a client-server computing technique may be used.

22 FIG. 21 FIG. 22 FIG. 80 1 80 1110 1120 1000 1140 1150 1160 1110 80 1110 80 1110 1110 is a block diagram showing an example of the camera module EDincluded in the electronic apparatus EDof. Referring to, the camera module EDmay include a lens assembly, a flash, an image sensor, an image stabilizer, a memory(buffer memory, etc.), and/or an image signal processor. The lens assemblymay collect light emitted from an object that is to be captured. The camera module EDmay include a plurality of lens assemblies, and in this case, the camera module EDmay include a dual camera module, a 360-degree camera, or a spherical camera. Some of the plurality of lens assembliesmay have the same lens properties (viewing angle, focal distance, auto-focus, F number, optical zoom, etc.) or different lens properties. The lens assemblymay include a wide-angle lens or a telephoto lens.

1120 1120 1120 1000 1110 1 FIG. The flashmay emit light that is used to strengthen the light emitted or reflected from the object. The flashmay emit visible light or infrared-ray light. The flashmay include one or more light-emitting diodes (red-green-blue (RGB) LED, white LED, infrared LED, ultraviolet LED, etc.), and/or a Xenon lamp. The image sensormay be the image sensor described above with reference to, and converts the light emitted or reflected from the object and transferred through the lens assemblyinto an electrical signal to obtain an image corresponding to the object.

1140 80 1101 80 1110 1000 1000 1140 80 1 80 1140 The image stabilizer, in response to a motion of the camera module EDor the electronic apparatusincluding the camera module ED, moves one or more lenses included in the lens assemblyor the image sensorin a certain direction or controls the operating characteristics of the image sensor(adjusting of a read-out timing, etc.) in order to compensate for a negative influence of the motion. The image stabilizermay sense the movement of the camera module EDor the electronic apparatus EDby using a gyro sensor (not shown) or an acceleration sensor (not shown) arranged in or out of the camera module ED. The image stabilizermay be implemented as an optical type.

1150 1000 1150 1160 1150 30 1 The memorymay store some or entire data of the image obtained through the image sensorfor next image processing operation. For example, when a plurality of images are obtained at a high speed, obtained original data (Bayer-patterned data, high resolution data, etc.) is stored in the memory, and a low resolution image is only displayed. Then, original data of a selected image (user selection, etc.) may be transferred to the image signal processor. The memorymay be integrated with the memory EDof the electronic apparatus ED, or may include an additional memory that is operated independently.

1160 1000 1150 1160 1000 80 1160 1150 80 30 60 2 4 8 1160 20 20 1160 20 1160 20 60 The image signal processormay perform image treatment on the image obtained through the image sensoror the image data stored in the memory. The image treatments may include a depth map generation, a three-dimensional modeling, a panorama generation, extraction of features, an image combination, and/or an image compensation (noise reduction, resolution adjustment, brightness adjustment, blurring, sharpening, softening, etc.). The image signal processormay perform controlling (exposure time control, read-out timing control, etc.) of the elements (image sensor, etc.) included in the camera module ED. The image processed by the image signal processormay be stored again in the memoryfor additional process, or may be provided to an external element of the camera module ED(e.g., the memory ED, the display device ED, the electronic apparatus ED, the electronic apparatus ED, the server ED, etc.). The image signal processormay be integrated with the processor ED, or may be configured as an additional processor that is independently operated from the processor ED. When the image signal processoris configured as an additional processor separately from the processor ED, the image processed by the image signal processorundergoes through an additional image treatment by the processor EDand then may be displayed on the display device ED.

1160 1000 1160 1110 1110 1000 Also, the image signal processormay receive two output signals independently from the adjacent photosensitive cells in each pixel or sub-pixel of the image sensor, and may generate an auto-focusing signal from a difference between the two output signals. The image signal processormay control the lens assemblyso that the focus of the lens assemblymay be accurately formed on the surface of the image sensorbased on the auto-focusing signal.

1 80 80 80 80 80 22 FIG. The electronic apparatus EDmay further include one or a plurality of camera modules having different properties or functions. The camera module may include elements similar to those of the camera module EDof, and the image sensor included in the camera module may be implemented as a charge coupled device (CCD) sensor and/or a complementary metal oxide semiconductor (CMOS) sensor and may include one or a plurality of sensors selected from the image sensors having different properties, such as an RGB sensor, a black and white (BW) sensor, an IR sensor, or a UV sensor. In this case, one of the plurality of camera modules EDmay include a wide-angle camera and another camera module EDmay include a telephoto camera. Similarly, one of the plurality of camera modules EDmay include a front camera and another camera module EDmay include a rear camera.

1000 1200 1300 1400 1500 1600 1200 1300 23 FIG. 24 FIG. 25 FIG. 26 FIG. 27 FIG. The image sensoraccording to the example embodiments may be applied to a mobile phone or a smartphoneshown in, a tablet or a smart tabletshown in, a digital camera or a camcordershown in, a laptop computershown in, or a television or a smart televisionshown in. For example, the smartphoneor the smart tabletmay include a plurality of high-resolution cameras each including a high-resolution image sensor. Depth information of objects in an image may be extracted, out focusing of the image may be adjusted, or objects in the image may be automatically identified by using the high-resolution cameras.

1000 1700 1800 1900 2000 1700 1800 1900 2000 28 FIG. 29 FIG. 30 FIG. 31 FIG. Also, the image sensormay be applied to a smart refrigeratorshown in, a surveillance camerashown in, a robotshown in, a medical camerashown in, etc. For example, the smart refrigeratormay automatically recognize food in the refrigerator by using the image sensor, and may notify the user of an existence of a certain kind of food, kinds of food put into or taken out, etc. through a smartphone. Also, the surveillance cameramay provide an ultra-high-resolution image and may allow the user to recognize an object or a person in the image even in dark environment by using high sensitivity. The robotmay be input to a disaster or industrial site that a person may not directly access, to provide the user with high-resolution images. The medical cameramay provide high-resolution images for diagnosis or surgery, and may dynamically adjust a field of view.

1000 2100 2100 2110 2120 2130 2140 2110 2120 2130 2140 2100 2100 2000 2110 2120 2130 2140 32 FIG. Also, the image sensormay be applied to a vehicleas shown in. The vehiclemay include a plurality of vehicle cameras,,, andat various locations. Each of the vehicle cameras,,, andmay include the image sensor according to the one or more example embodiments. The vehiclemay provide a driver with various information about the interior of the vehicleor the periphery of the vehicleby using the plurality of vehicle cameras,,, and, and may provide the driver with the information necessary for the autonomous travel by automatically recognizing an object or a person in the image.

While the image sensor including the nano-photonic microlens array and the electronic apparats including the image sensor have been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims. The preferred embodiments should be considered in descriptive sense only and not for purposes of limitation. Therefore, the scope of the disclosure is defined not by the detailed description of the disclosure but by the appended claims, and all differences within the scope will be construed as being included in the present disclosure.

It should be understood that embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments. While one or more example embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.